Method and apparatus for indicating channel access

ABSTRACT

The present disclosure discloses a method and an apparatus for indicating channel access. The method includes: receiving first indication information transmitted by a network device; and obtaining one or more channel access parameters based on the first indication information. The one or more channel access parameters are used for determining channel access for a target uplink transmission. The first indication information transmitted by the network device is received, and the first indication information may be based on a command field in existing information, without the need for a new command field for indicating channel access for the target uplink transmission.

CROSS-REFERENCE TO RELATED APPLICATION

The present application is a continuation of International ApplicationNo. PCT/CN2019/111781, filed on Oct. 17, 2019, which is herebyincorporated by reference in its entireties.

TECHNICAL FIELD

The present disclosure relates to communication technology, and moreparticularly, to a method and an apparatus for indicating channelaccess.

BACKGROUND

The unlicensed spectrum is assigned by countries and regions for radiodevice communication. This spectrum is usually considered to be a sharedspectrum, that is, communication devices in different communicationsystems can use this spectrum as long as they meet regulatoryrequirements set by the countries or regions for the spectrum, withoutthe need to apply for a proprietary spectrum authorization fromgovernments.

In order to allow various communication systems that use the unlicensedspectrum for wireless communication to coexist friendly on thisspectrum, some countries or regions have stipulated legal requirementsthat must be met when using the unlicensed spectrum. For example, acommunication device shall follow a “Listen Before Talk (LBT)”principle, that is, the communication device needs to listen to achannel on the unlicensed spectrum before transmitting signals on thechannel. Only when the result of the channel listening indicates thatthe channel is idle, the communication device can transmit signals. Ifthe result of the channel listening by the communication device on thechannel over the unlicensed spectrum indicates that the channel is busy,the communication device cannot transmit signals.

Therefore, on the unlicensed spectrum, a type of LBT needs to beindicated during a random access procedure. However, this will increasethe bit overhead, and the size of information on the unlicensed spectrumis inconsistent with the size of information on the licensed spectrum.

SUMMARY

The present disclosure provides a method and an apparatus for indicatingchannel access, capable of solving the problem associated with theincrease in the bit overhead and the inconsistency between the size ofinformation on the unlicensed spectrum and the size of information onthe licensed spectrum.

In a first aspect, a method for indicating channel access is providedaccording to an embodiment of the present disclosure. The method isapplied in a terminal device and includes: receiving first indicationinformation transmitted by a network device; and obtaining one or morechannel access parameters based on the first indication information. Theone or more channel access parameters are used for determining channelaccess for a target uplink transmission.

In a second aspect, a method for indicating channel access is providedaccording to an embodiment of the present disclosure. The method isapplied in a network device and includes: transmitting first indicationinformation to a terminal device. The first indication information isused for obtaining one or more channel access parameters. The one ormore channel access parameters are used for determining channel accessfor a target uplink transmission.

In a third aspect, an apparatus for indicating channel access isprovided. The apparatus includes: a receiving module configured toreceive first indication information transmitted by a network device;and an obtaining module configured to obtain one or more channel accessparameters based on the first indication information. The one or morechannel access parameters are used for determining channel access for atarget uplink transmission.

In a fourth aspect, an apparatus for indicating channel access isprovided. The apparatus includes: a transmitting module configured totransmit first indication information to a terminal device. The firstindication information is used for obtaining one or more channel accessparameters. The one or more channel access parameters are used fordetermining channel access for a target uplink transmission.

In a fifth aspect, a terminal device is provided according to anembodiment of the present disclosure. The terminal device includes aprocessor and a memory. The memory is configured to store a programexecutable on the processor. The program, when executed by theprocessor, causes the processor to perform the method for indicatingchannel access according to any of the above aspects.

In a sixth aspect, a computer readable storage medium is providedaccording to an embodiment of the present disclosure. The computerreadable storage medium stores a computer program which, when executed,implements the method for indicating channel access according to any ofthe above aspects.

In a seventh aspect, a computer program product is provided according toan embodiment of the present disclosure. The computer program product isstored in a non-transitory computer readable storage medium. Thecomputer program product, when executed, implements the method forindicating channel access according to any of the above aspects.

In an eighth aspect, a chip is provided according to an embodiment ofthe present disclosure. The chip includes a processor. The processor isconfigured to invoke and execute a computer program from a memory tocause a device provided with the chip to perform the method forindicating channel access according to any of the above aspects.

In a ninth aspect, a computer program is provided according to anembodiment of the present disclosure. The computer program, whenexecuted, implements the method for indicating channel access accordingto any of the above aspects.

The solutions according to the embodiments of the present disclosure mayhave the following advantageous effects.

First indication information transmitted by a network device isreceived, and one or more channel access parameters are obtained basedon the first indication information. The one or more channel accessparameters are used for determining channel access for a target uplinktransmission. The first indication information transmitted by thenetwork device is received, and the first indication information may bebased on a command field in existing information, without the need for anew command field for indicating channel access for the target uplinktransmission. In this way, the bit overhead of the information can bereduced and the complexity in design and implementation can be reduced,thereby solving the problem associated with the inconsistency betweenthe size of information on the unlicensed spectrum and the size ofinformation on the licensed spectrum and the high bit overhead ofinformation on the unlicensed spectrum.

It should be understood that the above general description and thefollowing detailed description are only exemplary and are not intendedto limit the present disclosure.

BRIEF DESCRIPTION OF DRAWINGS

The drawings, which are incorporated into the description and constitutea part of the description, show embodiments of the present disclosure,and are provided for explaining the principle of the present disclosurealong with the description.

FIG. 1 is a schematic diagram showing a network architecture of acommunication system where the embodiments of the present disclosure maybe applied.

FIG. 2 is a flowchart illustrating a method for indicating channelaccess according to an embodiment of the present disclosure.

FIG. 3 is a flowchart illustrating a method for indicating channelaccess according to an embodiment of the present disclosure.

FIG. 4 is a block diagram of an apparatus for implementing a method forindicating channel access according to any of the embodiments of thepresent disclosure.

FIG. 5 is a block diagram of an apparatus for implementing a method forindicating channel access according to any of the embodiments of thepresent disclosure.

FIG. 6 is a schematic diagram showing a hardware structure of anapparatus for indicating channel access according to Embodiment 5 of thepresent disclosure.

DESCRIPTION OF EMBODIMENTS

Here, the exemplary embodiments will be described in detail, withexamples thereof shown in the figures. When the following descriptionrefers to the figures, unless indicated otherwise, same numbers indifferent figures represent same or similar elements. Theimplementations described in the following exemplary embodiments do notrepresent all implementations that are consistent with the embodimentsof the present disclosure. On the contrary, they are only examples ofmethods and apparatus consistent with some aspects of the presentdisclosure as defined in the claims as attached. All other embodimentsobtained by those skilled in the art based on the embodiments of thepresent disclosure without any inventive efforts are to be encompassedby the scope of the present disclosure.

FIG. 1 shows a system architecture of a communication system where thefollowing embodiments of the present disclosure may be applied. Thesystem architecture includes a base station A and a user terminal B.

A four-step process is used in a random access procedure between theuser terminal B and the base station A.

In the first step, the user terminal B transmits a random accesspreamble sequence (message 1 or Msg1) to the base station A.

In the second step, upon detecting that the user terminal B transmitsthe access preamble sequence, the base station A transmits a RandomAccess Response (RAR), i.e., message 2 (Msg2), to the user terminal B toinform the user terminal B of an uplink resource it can use fortransmitting a message 3 (Msg3), assign Radio Network TemporaryIdentifier (RNTI) to the user terminal B, and provide a time advancecommand to the user terminal B. If the user terminal B fails to detectthe RAR in an RAR window, it retransmits a Physical Random AccessChannel (PRACH) sequence. If the user terminal B detects the RAR in theRAR window, the user terminal B transmits the Msg3 in accordance withuplink grant information indicated in the RAR.

In the third step, after the user terminal B receives the RAR, ittransmits the Msg3 in the uplink resource specified in the RAR message.This step allows Hybrid Automatic Repeat-reQuest (HARQ) basedretransmission.

In the fourth step, the base station A transmits a Msg4 to the userterminal B, containing a contention resolution message and allocatinguplink transmission resources for the user terminal B. This step allowsHARQ based retransmission. When the user terminal B receives the Msg4transmitted by the base station A, it detects whether Msg4 includes apart of the Msg3 transmitted by the user terminal B. If not, itindicates that the random access procedure of the user terminal B hassucceeded, otherwise it is considered that the random access procedurehas failed, and the user terminal B needs to initiate the random accessprocedure again from the first step.

In the four-step random access procedure, the RAR transmitted by thebase station A to the user terminal B is a response to the Msg1, and theRandom Access RNTI (RA-RNTI) used by the base station A whentransmitting the RAR is calculated based on the position of thetime-frequency resource of the PRACH. The Physical Downlink SharedChannel (PDSCH) corresponding to the Physical Downlink Control Channel(PDCCH) scrambled by the RA-RNTI can include responses to one or morepreamble sequences (or in other words, the PDSCH may include one or moreRAR messages each being a response to one preamble sequence). Inparticular, each RAR message includes, among other, a preamble sequence(Identity Document) ID, a Time Advance (TA) command, an uplink (UL)grant, and a (Temporary Cell-RNTI (TC-RNTI). Here, the UL grantincludes, among others, the following scheduling information: afrequency hopping flag, a Physical Uplink Shared Channel (PUSCH)frequency resource allocation, a PUSCH time resource allocation, aModulation and Coding Scheme (MCS), a Transmit Power Control (TPC)command for PUSCH, and a Channel State Information (CSI) request.

The size of each RAR is fixed at 56 bits, including:

R: Reserved bit, set to “0”,

TA command: 12 bits,

UL Grant: 27 bits, and

TC-RNTI: 16 bits.

Table 1 shows the specific information of the 27-bit UL grant in eachRAR:

TABLE 1 RAR grant field Number of bits Frequency hopping flag 1 PUSCHfrequency resource allocation 14 PUSCH time resource allocation 4 MCS 4TPC command for PUSCH 3 CSI request 1

As shown in Table 1, the UL grant in RAR includes:

Frequency hopping flag: 1 bit,

PUSCH frequency resource allocation: 14 bits,

PUSCH time resource allocation: 4 bits,

MCS: 4 bits,

TPC command for PUSCH: 3 bits, and

CSI request: 1 bit.

On the unlicensed spectrum, a downlink transmission opportunity refersto a set of downlink transmissions (i.e., including one or more downlinktransmissions) performed by the base station A. The set of downlinktransmissions refers to continuous transmissions (i.e., no intervalbetween the downlink transmissions), or there is an interval betweendownlink transmissions but the interval is shorter than or equal to 16μs (microseconds). If the interval between two downlink transmissionsperformed by the base station is greater than 16 μs, then the twodownlink transmissions are considered as belonging to two downlinktransmission opportunities.

In the four-step random access procedure on the unlicensed spectrum, LBTis needed before each step of transmission. After the user terminal Btransmits the PRACH sequence (Msg1) to the base station A, the userterminal B needs to receive the RAR information (Msg2) from the basestation A, and transmits the Msg3 in accordance with the RARinformation. Here, the user terminal B needs to perform LBT inaccordance with an LBT mode indicated in the RAR information beforetransmitting the Msg3.

The LBT modes on the unlicensed spectrum include Category 1 (Cat-1) LBT,Category 2 (Cat-2) LBT, Category 3 (Cat-3) LBT, and Category 4 (Cat-4)LBT, in which:

Cat-1 LBT means that a communication device can transmit without channeldetection after an interval.

Cat-2 LBT means that a communication device performs a single-slotchannel detection. In particular, Cat-2 LBT can include 25 μssingle-slot channel detection and 16 μs single-slot channel detection.

Cat-3 LBT means that a communication devices performs a multi-slotchannel detection with random back-off based on a fixed contentionwindow size.

Cat-4 LBT means that a communication device performs a multi-slotchannel detection with random back-off based on adjustment of thecontention window size. In particular, Cat-4 LBT can include differentchannel access priorities (Channel Access Priority Classes (CAPCs))depending on priorities of services to be transmitted. Table 2 shows thechannel access parameters corresponding to different CAPCs for Cat-4LBT. The smaller the value of p, the higher the CAPC.

TABLE 2 CAPC Allowed value (p) m_(p) CW_(min, p) CW_(max, p) T_(mcot, p)of CW_(p) 1 2 3 7 2 ms {3, 7} 2 2 7 15 4 ms {7, 15} 3 3 15 1023 6 or 10ms {15, 31, 63, 127, 255, 511, 1023} 4 7 15 1023 6 or 10 ms {15, 31, 63,127, 255, 511, 1023}

It is to be noted that in the above Table 2, m_(p) denotes the number ofback-off slots corresponding to the CAPC p, CW_(p) denotes thecontention window size corresponding to the CAPC p, CW_(min,p) denotesthe minimum value of CW_(p) corresponding to the CAPC p, CW_(max,p)denotes the maximum value of CW_(p) corresponding to the CAPC p, andT_(mcot,p) denotes the maximum channel occupied time lengthcorresponding to the CAPC p.

The CAPC p is determined based on a Quality of Service (QoS) ClassIdentifier (QCI) of the service. The specific mapping relationship isshown in Table 3 below:

TABLE 3 Channel Access Priority Class (p) QCI 1 1, 3, 5, 65, 66, 69, 702 2, 7 3 4, 6, 8, 9 4 —

It is also to be noted that when the user terminal B is scheduled totransmit PUSCH, regardless of the LBT mode to be used by the userterminal B, the user terminal B expects the base station A to indicatethe LBT mode and the CAPC p for PUSCH transmission. Here, if the LBTmode indicated by the base station A is Cat-4, the CAPC p is thepriority that the base station A indicates to the user terminal B foruse in channel access. If the LBT mode indicated by the base station Ais Cat-2, the CAPC p is the CAPC used by the base station A whenoccupying the channel.

In the random access procedure, the random access response informationneeds to include the indication information of the LBT category on theunlicensed spectrum when the User Equipment (UE) transmits the Msg3.Currently, the size of each RAR is fixed. If the indication informationis to be directly added to the RAR, the size of the RAR would becomelarger. In this case, the size of the RAR on the unlicensed spectrumwould be larger than the size of the RAR on the licensed spectrum, suchthat the RAR on the unlicensed spectrum and the RAR on the licensedspectrum cannot be transmitted via the same PDSCH, and the overhead ofthe RAR on the unlicensed spectrum would be relatively larger. Thefollowing embodiments of the present disclosure will describe in detailhow to determine channel access by the user terminal B for the Msg3 inthe random access procedure without changing the size of the RAR on thelicensed spectrum by the base station A.

In this system architecture, the exemplary communication system can beGlobal System of Mobile communication (GSM), Code Division MultipleAccess (CDMA) system, Wideband Code Division Multiple Access (WCDMA)system, General Packet Radio Service (GPRS), Long Term Evolution (LTE)system, LTE Frequency Division Duplex (FDD) system, LTE Time DivisionDuplex (TDD) system, Advanced Long Term Evolution (LTE-A) system, NewRadio (NR) system, evolved NR system, LTE-based access to unlicensedspectrum (LTE-U) system, New Radio based access to unlicensed spectrum(NR-U) system, Universal Mobile Telecommunication System (UMTS),Worldwide Interoperability for Microwave Access (WiMAX) communicationsystem, Wireless Local Area Network (WLAN), Wireless Fidelity (WiFi),next generation communication system, or other communication systems.

Generally, traditional communication systems can support a limitednumber of connections and are easy to implement. However, with thedevelopment of communication technology, mobile communication systemscan support not only traditional communications, but also e.g., Deviceto Device (D2D) communication, Machine to Machine (M2M) communication,and Machine Type Communication (MTC), Vehicle to Vehicle (V2V)communication, etc. The embodiments of the present disclosure can alsobe applied to these communication systems.

In particular, this exemplary communication system can include a networkdevice and a terminal. When the terminal accesses the mobilecommunication network provided by the network device, the terminal andthe network device can be connected via a wireless communication link,and the communication connection mode can be a single connection mode, adual connection mode, or a multi-connection mode. When the communicationconnection mode is the single connection mode, the network device can bean LTE base station or an NR base station (also known as gNB). When thecommunication mode is the dual connection mode (which can be achievedwith the Carrier Aggregation (CA) technology or by a plurality ofnetwork devices), and the terminal is connected to a plurality ofnetwork devices, the plurality of network devices can include a masterbase station (Master Cell Group (MCG)) and a secondary base station(Secondary Cell Group (SCG)). The base stations communicate data via abackhaul link. The master base station may be an LTE base station, andthe secondary base station may be an LTE base station. Alternatively,the master base station may be an NR base station, and the secondarybase station may be an LTE base station. Alternatively, the master basestation may be an NR base station, and the secondary base station may bean NR base station. The receiving-side RLC entity as described in theembodiments of the present disclosure may be a terminal or software(such as a protocol stack) and/or hardware (such as a modem) in theterminal. Similarly, the transmitting-side RLC entity may be a networkdevice or software (such as protocol stack) and/or hardware (such asmodem) in the network device.

In the embodiments of the present disclosure, the terms “network” and“system” are often used interchangeably, and those skilled in the artcan understand their meanings.

The user terminals as described in the embodiments of the presentdisclosure may include various handheld devices with wirelesscommunication functions, vehicle-mounted devices, wearable devices,computing devices, or other processing devices connected to wirelessmodems, as well as various forms of User Equipments (UEs), MobileStations (MSs), terminal devices, etc. For the purpose of description,the devices mentioned above can be collectively referred to asterminals.

In addition, the terms “system” and “network” are often usedinterchangeably herein. The term “and/or” as used herein only representsa relationship between correlated objects, including threerelationships. For example, “A and/or B” may mean A only, B only, orboth A and B. In addition, the symbol “/” as used herein represents an“or” relationship between the correlated objects preceding andsucceeding the symbol.

It can be appreciated that, in the embodiments of the presentdisclosure, “B associated with A” means that B is associated with A, andB can be determined from A. However, it can also be appreciated that Bbeing determined from A does not mean that B can be determined from Aonly, but can be determined from A and/or other information.

FIG. 2 is a flowchart of a method for indicating channel accessaccording to an embodiment of the present disclosure. As shown in FIG.2, the method for indicating channel access is applied to a terminaldevice, and may include the following steps.

At block 130, first indication information transmitted by a networkdevice is received.

Here, the terminal device or UE receives the first indicationinformation transmitted by the network device. The first indicationinformation indicates one or more channel access parameters. The channelaccess parameters are used for determining channel access for a targetuplink transmission. The one or more channel access parameters include achannel access mode and a channel access priority. At block 150, the oneor more channel access parameters are obtained in accordance with thefirst indication information.

Here, the one or more channel access parameter are used for determiningchannel access for the target uplink transmission. The channel accessfor the target uplink transmission can be determined based on a channelaccess mode and a channel access priority in the one or more channelaccess parameters.

In this embodiment, by receiving the first indication informationtransmitted by the network device, the one or more channel accessparameters can be obtained from the first indication information.

FIG. 3 is a flowchart of a method for indicating channel accessaccording to an embodiment of the present disclosure. As shown in FIG.3, the method includes the following steps.

At block 110, first indication information is transmitted.

Here, the first indication information includes mode informationindicating a channel access mode and/or priority information indicatinga channel access priority, such that the channel access mode and thechannel access priority indicated in the first indication informationcan be determined based on the mode information and the priorityinformation in the first indication information. One or more channelaccess parameters are determined based on the channel access mode andthe channel access priority, and then channel access for a target uplinktransmission is determined.

The target uplink transmission can be a message 3 (Msg3) in a randomaccess procedure. The first indication information can be carried in aRandom Access Response (RAR) message only, or in Downlink ControlInformation (DCI) only, or in both the RAR message and the DCI. Here,DCI is used to schedule the RAR message.

In at least one embodiment, when the first indication information iscarried in the DCI scheduling the RAR message, the RAR message includesat least one RAR scheduled Msg3 that uses the one or more channel accessparameters indicated in the first indication information in the DCI forLBT. In an exemplary embodiment, all RAR scheduled Msg3s included in theRAR message use the one or more channel access parameters indicated inthe first indication information in the DCI for LBT.

In at least one embodiment, the first indication information may beobtained by reusing a part or all of bits in a frequency resourceallocation command field in an uplink grant in the RAR message.

In at least one embodiment, the first indication information may beobtained by reusing bits in a frequency hopping flag command field inthe uplink grant in the RAR message.

In at least one embodiment, when the frequency hopping flag commandfield is not used to indicate whether to perform frequency hopping, thefirst indication information may be obtained by reusing the bits in thefrequency hopping flag command field in the uplink grant in the RARmessage and/or reusing a part or all of the bits in the frequencyresource allocation command field in the uplink grant in the RARmessage.

In at least one embodiment, when the frequency hopping flag commandfield is used to indicate whether to perform frequency hopping, thefirst indication information may be obtained by reusing a part or all ofthe bits in the frequency resource allocation command field in theuplink grant in the RAR message.

In at least one embodiment, when the first indication information reusesa part of the bits in the frequency resource allocation command field inthe uplink grant in the RAR message, the part of bits may be at thebeginning of the frequency resource allocation field or at the end ofthe frequency resource allocation field.

In at least one embodiment, the first indication information can also beobtained by reusing a part or all of bits in another redundant commandfield in the uplink grant in the RAR message. As an example, the otherredundant command field may include a power control command field (e.g.,TPC command for PUSCH) and/or a CSI request field.

In at least one embodiment, the first indication information may be anewly added information field in the uplink grant in the RAR message.

In at least one embodiment, the first indication information is obtainedvia a time resource allocation command field in an uplink grant in theRAR message. A time resource allocation indicated in the time resourceallocation command field has a mapping relationship with the one or morechannel access parameters.

In at least one embodiment, a time resource allocation command field inthe uplink grant in the RAR message has in total 4 bits. A mappingrelationship between time resource allocations indicated in the timeresource allocation command field in the uplink grant in the RAR messageand channel access parameters can be configured. Therefore, when the RARmessage is received, the one or more channel access parameters can beobtained based on the mapping relationship between the time resourceallocations indicated in the time resource allocation command field inthe uplink grant in the RAR message and the channel access parameters.

In an embodiment, a 4-bit PUSCH time resource allocation informationfield is indicated in the RAR uplink grant, and the network canconfigure the correspondence between PUSCH time resource allocations andchannel access parameters in this example. After receiving the PUSCHtime resource allocation in the RAR uplink grant, the UE can determinethe corresponding channel access parameter(s).

In at least one embodiment, the first indication information may alsoindicate a starting position of the target uplink transmission.

In at least one embodiment, the starting position of the target uplinktransmission may include at least one of the following positions: astarting boundary of a first symbol, a position after the startingboundary of the first symbol and having a distance of 16 μs from thestarting boundary of the first symbol, a position after the startingboundary of the first symbol and having a distance of 16 μs plus alength of a time advance from the starting boundary of the first symbol,a position after the starting boundary of the first symbol and having adistance of 25 μs from the starting boundary of the first symbol, aposition after the starting boundary of the first symbol and having adistance of 25 μs plus a length of a time advance from the startingboundary of the first symbol, a starting boundary of a second symbolwhich follows the first symbol and is adjacent to the first symbol.

In at least one embodiment, the second symbol is the first valid uplinksymbol in the target uplink transmission.

In at least one embodiment, when the starting position of the targetuplink transmission is in the first symbol, the transmission from thestarting position to the starting boundary of the second symbol is anextended cyclic prefix of the second symbol.

At block 130, the first indication information transmitted by thenetwork device is received.

At block 150, one or more channel access parameters are obtained basedon the first indication information.

In an embodiment of the present disclosure, the first indicationinformation may indicate the one or more channel access parameters, andthe channel parameters determined from the first indication informationmay include one of the following:

1. Cat-1 LBT, Cat-2 LBT with detection interval of 16 μs, Cat-2 LBT withdetection interval of 25 μs, or a first priority in Cat-4 LBT;

2. Cat-1 LBT, Cat-2 LBT with detection interval of 16 μs, Cat-2 LBT withdetection interval of 25 μs, Cat-4 LBT Priority 1, Cat-4 LBT Priority 2,Cat-4 LBT Priority 3, or Cat-4 LBT Priority 4;

3. Channel access mode and channel access priority, the channel accessmode including: Cat-1 LBT, Cat-2 LBT with detection interval of 16 μs,Cat-2 LBT with detection interval of 25 μs, or Cat-4 LBT, and thechannel access priority including Cat-4 LBT Priority 1, Cat-4 LBTPriority 2, Cat-4 LBT Priority 3, and Cat-4 LBT Priority 4; or

4. Channel access priority, the channel access priority including Cat-4LBT Priority 1, Cat-4 LBT Priority 2, Cat-4 LBT Priority 3, and Cat-4LBT Priority 4.

The above situations will be described in detail below.

1. Cat-1 LBT, Cat-2 LBT with Detection Interval of 16 μs, Cat-2 LBT withDetection Interval of 25 μs, or a First Priority in Cat-4 LBT.

Here, the first priority in Cat-4 LBT can be predetermined or configuredby the network device. In at least one embodiment, the value of thefirst priority may include one of 1, 2, 3, and 4 in Table 2.

As an example, the first priority in Cat-4 LBT can be predetermined tobe Cat-4 LBT Priority 1, which is the highest priority, or the firstpriority in Cat-4 LBT can be determined based on a service to betransmitted with the lowest priority in the target uplink transmission.

The target uplink transmission can be a Msg3 in the random accessprocedure, and the Msg3 corresponds to a channel access priority inCat-4 LBT. In an initial access process, when the base station receivesa PRACH sequence transmitted by the UE, the base station cannotdetermine the content of the Msg3 to be transmitted by the UEtransmitting the PRACH sequence, and therefore cannot determine the QCIof the Msg3, and thus cannot determine the channel access prioritycorresponding to the Msg3. Therefore, in at least one embodiment, apriority can be fixed for the LBT corresponding to the Msg3transmission. For example, the priority of Msg3 transmission may beCat-4 LBT Priority 2.

In at least one embodiment, the priority when uplink data of the UE isincluded in the Msg3 is lower than the priority when no uplink data ofthe UE is included in the Msg3. It should be understood that the smallerthe value of priority, the higher the priority. For example, when theuplink data of the UE is included in the Msg3, the correspondingpriority is Cat-4 LBT Priority p1, and when no uplink data of the UE isincluded in the Msg3, the corresponding priority is Cat-4 LBT priorityP2, where p1 is greater than p2.

In this exemplary embodiment, the first indication information can be 2bits, and the first indication information can be obtained by reusing apart or all of bits in a frequency resource allocation command field inan uplink grant in the RAR message and/or by reusing bits in a frequencyhopping flag command field in the uplink grant in the RAR message.

2. Cat-1 LBT, Cat-2 LBT with Detection Interval of 16 μs, Cat-2 LBT withDetection Interval of 25 μs, Cat-4 LBT Priority 1, Cat-4 LBT Priority 2,Cat-4 LBT Priority 3, or Cat-4 LBT Priority 4.

Here, the target uplink transmission may be a Msg3 in the random accessprocedure. It should be understood that when the indicated LBT mode isnot Cat-4, the channel access priority is also indicated, which ismainly used in a scenario where a plurality of PUSCHs is continuouslytransmitted in the time domain in uplink, such that the transmission ofthe plurality of PUSCHs can be resumed in accordance with the indicatedchannel access priority after being interrupted. If for the Msg3 onlyone PUSCH is transmitted in the time domain in uplink, then when theindicated LBT mode is not Cat-4, the channel access priority indicationinformation is not needed. Therefore, if the LBT mode indicated in thefirst indication information is not Cat-4, there is no need to indicatethe channel access priority.

In this exemplary embodiment, the first indication information can be 3bits, and the first indication information can be obtained by reusing apart or all of bits in a frequency resource allocation command field inan uplink grant in the RAR message and/or by reusing bits in a frequencyhopping flag command field in the uplink grant in the RAR message.

3. Channel Access Mode and Channel Access Priority.

Here, the channel access mode includes: Cat-1 LBT, Cat-2 LBT withdetection interval of 16 μs, Cat-2 LBT with detection interval of 25 μs,or Cat-4 LBT, and the channel access priority includes: Cat-4 LBTPriority 1, Cat-4 LBT Priority 2, Cat-4 LBT Priority 3, and Cat-4 LBTPriority 4.

Here, the target uplink transmission may be a Msg3 in the random accessprocedure.

In at least one embodiment, if the LBT mode indicated in the firstindication information is Cat-4, the channel access priority indicatedin the first indication information is the priority that the basestation indicates to the UE for use in channel access.

In at least one embodiment, if the LBT mode indicated in the firstindication information is not Cat-4, the channel access priorityindicated in the first indication information is the channel accesspriority used by the base station when occupying the channel.

In an exemplary embodiment, when the first indication information iscarried in the RAR message and the DCI, the information indicating thechannel access mode in the first indication information is carried inthe DCI, and the priority information indicating the channel accesspriority in the first indication information is carried in the RARmessage.

In an exemplary embodiment, when the first indication information iscarried in the RAR message and the DCI, the information indicating thechannel access mode in the first indication information is carried inthe RAR message, and the priority information indicating the channelaccess priority in the first indication information is carried in theDCI.

As an example, when the one or more channel access parameters includethe channel access mode and the channel access priority, the firstindication information can be 4 bits, where 2 bits are the modeinformation indicating the channel access mode, and 2 bits are thepriority information indicating the channel access priority. Here, thereare 2 bits carried in the RAR message and 2 bits carried in the DCI.

In an exemplary embodiment, the first indication information may include4 bits, where 2 bits indicate the channel access mode, i.e., the LBTcategory, and 2 bits indicate the channel access priority, i.e., the LBTpriority. The LBT priority may include Cat-4 LBT Priority 1, Cat-4 LBTPriority 2, Cat-4 LBT Priority 3, and Cat-4 LBT Priority 4. Table 4shows an example of the first indication information in an exemplaryembodiment.

TABLE 4 LBT Category LBT Priority p (2 bits) (2 bits) 00 25 μs Cat-2 p =1 01 Cat-4 p = 2 10 16 μs Cat-2 p = 3 11 Cat-1 p = 4

4. Channel Access Priority, the Channel Access Priority Including Cat-4LBT Priority 1, Cat-4 LBT Priority 2, Cat-4 LBT Priority 3, and Cat-4LBT Priority 4.

Here, when the channel access parameter indicated in the firstindication information is the channel access priority, the channelaccess mode in the channel access parameter indicated in the firstindication information is Cat-4 LBT by default. The channel accesspriority indicated in the first indication information includes Cat-4LBT Priority 1, Cat-4 LBT Priority 2, Cat-4 LBT Priority 3, and Cat-4LBT Priority 4.

In a specific implementation of this embodiment, the first indicationinformation can be 2 bits, and the first indication information can beobtained by reusing a part or all of bits in a frequency resourceallocation command field in an uplink grant in the RAR message and/or byreusing bits in a frequency hopping flag command field in the uplinkgrant in the RAR message.

In an exemplary embodiment, the first indication information may have Nbits, and the first indication information may be obtained by reusing Nbits in the frequency resource allocation command field in the uplinkgrant in the RAR message. The N bits may be the first N bits in thefrequency resource allocation field or the last N bits in the frequencyresource allocation field. In this case, the uplink grant in the RARmessage is shown in Table 5 below.

TABLE 5 RAR grant field Number of bits Frequency hopping flag 1 Firstindication information N PUSCH frequency resource allocation 14 − NPUSCH time resource allocation 4 MCS 4 TPC command for PUSCH 3 CSIrequest 1

Here, the N bits in the frequency resource allocation command field inthe uplink grant can be used as the first indication information.

Once the one or more channel access parameters are obtained based on thefirst indication information, the target uplink transmission can beperformed in accordance with the one or more channel access parameters.

According to this embodiment, there is no need to add a new commandfield to indicate the LBT channel access for the Msg3, thereby reducingthe overhead of RAR and reducing the complexity of design andimplementation, and solving the problem associated with theinconsistency between the size of RAR on the unlicensed spectrum and thesize of RAR on the licensed spectrum and the high bit overhead of RAR onthe unlicensed spectrum.

In an exemplary embodiment, the method for indicating channel access isapplied to a terminal device, and may further include the following stepof: receiving second indication information transmitted by the networkdevice.

Here, the second indication information is used for determining afrequency resource allocation mode for the message 3 (Msg3).

In at least one embodiment, the second indication information may beobtained by reusing a part or all of bits in a frequency resourceallocation command field in an uplink grant in the RAR message; and/orby reusing bits in a frequency hopping flag command field in the uplinkgrant in the RAR message.

In at least one embodiment, the frequency resource allocation mode mayinclude: continuous resource allocation or comb resource allocation.

In at least one embodiment, the second indication information may becarried in the RAR message.

In at least one embodiment, when the frequency resource for transmittingthe Msg3 is comb resource allocation, the frequency hopping flag commandfield in the uplink grant in the RAR message is not used for indicatingwhether to apply frequency hopping or not. When the frequency resourcefor transmitting the Msg3 is continuous resource allocation, thefrequency hopping flag command field in the uplink grant in the RARmessage may be configured to not indicate whether to apply frequencyhopping or not.

In at least one embodiment, when the frequency hopping flag commandfield is not used for indicating whether to apply frequency hopping ornot, the second indication message may be obtained by reusing the bitsin the frequency hopping flag command field in the uplink grant in theRAR message and/or by reusing a part or all of the bits in the frequencyresource allocation command field in the uplink grant in the RARmessage. When the frequency hopping flag command field is used forindicating whether to apply frequency hopping or not, the secondindication message may be obtained by reusing a part or all of the bitsin the frequency resource allocation command field in the uplink grantin the RAR message. The part of the bits may be at the beginning of thefrequency resource allocation field, or may be at the end of thefrequency resource allocation field.

In at least one embodiment, the second indication information can alsobe obtained by reusing a part or all of bits in another redundantcommand field in the uplink grant in the RAR message. As an example, theother redundant command field may include a power control command field(e.g., TPC command for PUSCH) and/or a CSI request.

In at least one embodiment, the second indication information may be anewly added information field in the uplink grant in the RAR message.

In an exemplary embodiment, the first indication information may have Nbits, and the second indication information may have M bits. The firstindication information may be obtained by reusing N bits in thefrequency resource allocation command field in the uplink grant in theRAR message. The N bits may be the first N bits in the frequencyresource allocation domain, or may be the last N bits in the frequencyresource allocation domain.

The second indication information may be obtained by reusing a part orall of the bits in the frequency resource allocation command field inthe uplink grant in the RAR message. The M bits may be the first M bitsin the frequency resource allocation field, or may be the last M bits inthe frequency resource allocation field. In this case, the uplink grantin the RAR message is shown in Table 6 below.

TABLE 6 RAR grant field Number of bits Frequency hopping flag 1 Secondindication information M First indication information N PUSCH frequencyresource allocation 14 − N − M PUSCH time resource allocation 4 MCS 4TPC command for PUSCH 3 CSI request 1

Here, in the frequency resource allocation command field in the uplinkgrant, N bits are used as the first indication information, and M bitsare used as the second indication information.

In at least one embodiment, the value of M may be 1.

In this embodiment, the frequency resource allocation mode for the Msg3is determined based on the second indication information.

In an exemplary embodiment, the method for indicating channel access isapplied to a network device, and may further include the following stepof: transmitting the second indication information to the terminaldevice.

Here, the second indication information is used for determining thefrequency resource allocation mode of the message 3.

FIG. 4 is a block diagram of an apparatus for implementing a method forindicating channel access according to any of the embodiments of thepresent disclosure. The apparatus may be a terminal device. As shown inFIG. 4, the apparatus may include, but not limited to, a receivingmodule 230 and an obtaining module 250.

The receiving module 230 is configured to receive first indicationinformation transmitted by a network device.

The obtaining module 250 is configured to obtain one or more channelaccess parameters based on the first indication information. The one ormore channel access parameters are used for determining channel accessfor a target uplink transmission.

In an exemplary embodiment, the receiving module 230 can be furtherconfigured to receive second indication information transmitted by thenetwork device. The second indication information is used fordetermining a frequency resource allocation mode for a message 3.

For the implementation of the functions and operations of each of themodules in this embodiment and other parts that are not elaborated ordefined in detail, reference can be made to the description of the aboveembodiments, and details thereof will be omitted here.

FIG. 5 is a block diagram of an apparatus for implementing a method forindicating channel access according to any of the embodiments of thepresent disclosure. The apparatus may be a network device. As shown inFIG. 5, the apparatus may include, but not limited to, a transmittingmodule 310 configured to transmit first indication information to aterminal device. The first indication information is used for obtainingone or more channel access parameters.

The one or more channel access parameters are used for determiningchannel access for a target uplink transmission.

In an exemplary embodiment, the transmitting module 310 can be furtherconfigured to: transmit second indication information to the terminaldevice. The second indication information is used for determining afrequency resource allocation mode of a message 3.

In at least one embodiment, the network device may further include areceiving module 330 configured to receive the target uplinktransmission that is performed in accordance with the one or morechannel access parameters.

For the implementation of the functions and operations of each of themodules in this embodiment and other parts that are not elaborated ordefined in detail, reference can be made to the description of the aboveembodiments, and details thereof will be omitted here.

FIG. 6 is a schematic diagram showing a hardware structure of anapparatus for indicating channel access according to Embodiment 5 of thepresent disclosure. As shown in FIG. 6, a terminal device includes aprocessor 410 and a memory 420. The above components of the terminaldevice are communicatively connected with each other through a bussystem.

The processor 410 may be an independent component or a plurality ofprocessing elements. For example, it may be a CPU, an ASIC, or one ormore integrated circuits configured to implement the above methods, suchas at least one microprocessor or DSP, or at least one programmable gatearray or FPGA.

The memory 420 can store a program executable on the processor 410, andthe program, when executed by the processor 410, implements a part orall of the steps of the method for indicating channel access accordingto any of the above method embodiments.

An embodiment of the present disclosure also provides a computerreadable storage medium. The computer readable storage medium stores acomputer program which, when executed, implements a part or all of thesteps of the method for indicating channel access according to any ofthe above method embodiments.

An embodiment of the present disclosure also provides a computer programproduct. The computer program product is stored in a non-transitorycomputer readable storage medium. The computer program, when executed,implements a part or all of the steps of the method for indicatingchannel access according to any of the above method embodiments. Thecomputer program product may be a software installation package.

An embodiment of the present disclosure also provides a chip. The chipincludes a processor configured to invoke and execute a computer programfrom a memory, to cause a device provided with the chip to perform apart or all of the steps of the method for indicating channel accessaccording to any of the above method embodiments.

An embodiment of the present disclosure also provides a computer programwhich, when executed, implements a part or all of the steps of themethod for indicating channel access according to any of the abovemethod embodiments.

The steps of the method or algorithm described in any the embodiments ofthe present disclosure may be implemented in hardware, or may beimplemented by a processor executing software instructions. The softwareinstructions can be composed of corresponding software modules, whichcan be stored in a Random Access Memory (RAM), a flash memory, a ReadOnly Memory (ROM), an Erasable Programmable ROM (EPROM), an ElectricallyEPROM (EEPROM), a register, a hard disk, a portable hard disk, a CD-ROM,or any other form of storage medium known in the art. An exemplarystorage medium can be coupled to a processor, such that the processorcan read information from the storage medium and can write informationto the storage medium. Of course, the storage medium may also be anintegral part of the processor. The processor and the storage medium maybe located in an ASIC. In addition, the ASIC may be located in an accessnetwork device, a target network device, or a core network device. Ofcourse, the processor and the storage medium may also exist, as discretecomponents, in the access network device, the target network device, orthe core network device.

It can be appreciated by those skilled in the art that, in one or moreof the above examples, the functions described in the embodiments of thepresent disclosure may be implemented in whole or in part in software,hardware, firmware, or any combination thereof. When implemented bysoftware, they can be implemented in the form of a computer programproduct in whole or in part. The computer program product includes oneor more computer instructions. When the computer program instructionsare loaded and executed on a computer, the processes or functionsdescribed in the embodiments of the present disclosure are provided inwhole or in part. The computer may be a general purpose computer, anapplication specific computer, a computer network, or any otherprogrammable device. The computer instructions may be stored in acomputer-readable storage medium or transmitted from one computerreadable storage medium to another. For example, the computerinstructions may be transmitted from one website, computer, server, ordata center to another via a wired (such as coaxial cable, opticalfiber, Digital Subscriber Line (DSL)) or wireless (such as infrared,wireless, microwave, etc.) connection. The computer readable storagemedium may be any usable medium that can be accessed by a computer or adata storage device such as a server or a data center integrated withone or more usable medium. The usable medium may be a magnetic medium(for example, a floppy disk, a hard disk, a magnetic tape), an opticalmedium (for example, a Digital Video Disc (DVD)), or a semiconductormedium (for example, a Solid State Disk (SSD)), etc.

The embodiments above further describe the objects, technical solutions,and advantageous effects of the embodiments of the present disclosure indetail. It should be understood that the above are only specificimplementations of the embodiments of the present disclosure and are notintended to limit the scope of the embodiments of the presentdisclosure. Any modifications, equivalents, improvements, etc. that aremade on the basis of the technical solutions of the embodiments of thepresent disclosure are to be encompassed by the scope of the embodimentsof the present disclosure.

It should be understood that the present disclosure is not limited tothe specific structure that has been described above and shown in thefigure. Various modifications and changes can be performed withoutdeparting from the scope of the present disclosure, which is definedonly by the claims as attached.

What is claimed is:
 1. A method for indicating channel access, appliedin a terminal device, the method comprising: receiving first indicationinformation transmitted by a network device; and obtaining one or morechannel access parameters based on the first indication information, theone or more channel access parameters being used for determining channelaccess for a target uplink transmission.
 2. The method of claim 1,wherein the first indication information comprises: mode informationindicating a channel access mode.
 3. The method of claim 1, wherein thetarget uplink transmission comprises Message 3 in a random accessprocedure.
 4. The method of claim 3, wherein the first indicationinformation is carried in a Random Access Response (RAR) message.
 5. Themethod of claim 4, wherein the first indication information beingcarried in the RAR message comprises: the first indication informationbeing obtained by reusing a part of bits in a Physical Uplink SharedChannel (PUSCH) frequency resource allocation field in a RAR grant fieldin the RAR message.
 6. The method of claim 5, wherein the firstindication information being obtained by reusing a part of bits in thePUSCH frequency resource allocation field in the RAR grant field in theRAR message comprises: the first indication information occupying N bitsof the PUSCH frequency resource allocation field, which occupies 14 bitsin the RAR grant field.
 7. The method of claim 1, wherein the firstindication information occupies 2 bits.
 8. The method of claim 1,wherein the first indication information further indicates a startingposition of the target uplink transmission.
 9. The method of claim 8,wherein the starting position of the target uplink transmission includesone of: a starting boundary of a first symbol; a position after astarting boundary of a first symbol and having a distance of 16 μs plusa length of a time advance from the starting boundary of the firstsymbol; a position after a starting boundary of a first symbol andhaving a distance of 25 μfrom the starting boundary of the first symbol;a position after a starting boundary of a first symbol and having adistance of 25 μs plus a length of a time advance from the startingboundary of the first symbol; or a starting boundary of a second symbolthat follows a first symbol and is adjacent to the first symbol.
 10. Themethod of claim 9, when the starting position of the target uplinktransmission is in the first symbol, a transmission from the startingposition to the starting boundary of the second symbol is an extendedcyclic prefix of the second symbol.
 11. A method for indicating channelaccess, applied in a network device, the method comprising: transmittingfirst indication information to a terminal device, the first indicationinformation being used for obtaining one or more channel accessparameters, wherein the one or more channel access parameters are usedfor determining channel access for a target uplink transmission.
 12. Themethod of claim 11, wherein the first indication information comprises:mode information indicating a channel access mode.
 13. The method ofclaim 11, wherein the target uplink transmission comprises Message 3 ina random access procedure.
 14. The method of claim 13, wherein the firstindication information is carried in a Random Access Response (RAR)message.
 15. The method of claim 14, wherein the first indicationinformation being carried in the RAR message comprises: the firstindication information being obtained by reusing a part of bits in aPhysical Uplink Shared Channel (PUSCH) frequency resource allocationfield in a RAR grant field in the RAR message.
 16. The method of claim15, wherein the first indication information being obtained by reusing apart of bits in the PUSCH frequency resource allocation field in the RARgrant field in the RAR message comprises: the first indicationinformation occupying N bits of the PUSCH frequency resource allocationfield, which occupies 14 bits in the RAR grant field.
 17. The method ofclaim 11, wherein the first indication information occupies 2 bits. 18.The method of claim 11, wherein the first indication information furtherindicates a starting position of the target uplink transmission.
 19. Themethod of claim 18, wherein the starting position of the target uplinktransmission includes one of: a starting boundary of a first symbol; aposition after a starting boundary of a first symbol and having adistance of 16 μs plus a length of a time advance from the startingboundary of the first symbol; a position after a starting boundary of afirst symbol and having a distance of 25 μs from the starting boundaryof the first symbol; a position after a starting boundary of a firstsymbol and having a distance of 25 μs plus a length of a time advancefrom the starting boundary of the first symbol; or a starting boundaryof a second symbol that follows a first symbol and is adjacent to thefirst symbol.
 20. The method of claim 19, when the starting position ofthe target uplink transmission is in the first symbol, a transmissionfrom the starting position to the starting boundary of the second symbolis an extended cyclic prefix of the second symbol.
 21. A terminaldevice, comprising a processor and a memory, wherein the memory isconfigured to store a program executable on the processor, and theprogram, when executed by the processor, causes the processor to:receive first indication information transmitted by a network device;and obtain one or more channel access parameters based on the firstindication information, the one or more channel access parameters beingused for determining channel access for a target uplink transmission.